We　have　studied　the　role　of　external　current　stimuli　in　a　four-dimensional　Hodgkin-Huxley-type　model　of　cold　receptor　in　this　paper.　Firstly,　we　researched　its　firing　patterns　from　direct　current　(DC)　and　alternating　current　(AC)　stimuli.　Under　different　values　of　DC　stimulus　intensity,　interspike　intervals　(ISIs)　with　period-doubling　bifurcation　phenomena　appeared.　Second,　research　has　shown　that　neurons　are　extremely　sensitive　to　changes　in　the　frequency　and　amplitude　of　the　current　used　to　stimulate　them.　As　the　stimulus　frequency　increased,　discharge　rhythms　emerged　ranging　from　burst　firing　to　chaotic　firing　and　spiking　firing.　Meanwhile,　various　phase-locking　patterns　have　been　studied　in　this　paper,　such　as　p　:1　(p　＞　1),　1　:　q　(q　＞　1),　2　:　q　(q　＞　1)　and　p　:　q　(p,　q　＞　1),　etc.　Finally,　based　on　the　fast-slow　dynamics　analysis,　codimension-two　bifurcation　analysis　of　the　fast　subsystem　was　performed　in　the　parameter　(a(sr),　B)-plane.　We　mainly　investigated　cusp　bifurcation,　fold-Hopf　bifurcation,　Bogdanov-Takens　bifurcation　and　generalized　Hopf　bifurcation.　These　results　revealed　the　effect　of　external　current　stimuli　on　the　neuronal　discharge　rhythm　and　were　instructive　for　further　understanding　the　dynamical　properties　and　mechanisms　of　the　Huber-Braun　model.